Additional field In customer Registration API

I am using magento 2.1.5, and i am using default API for customer registration. now i added one more field “business” in registration page and want to add in API response also.

How to add this filed business in API.

DreamProxies - Cheapest USA Elite Private Proxies 100 Private Proxies 200 Private Proxies 400 Private Proxies 1000 Private Proxies 2000 Private Proxies ExtraProxies.com - Buy Cheap Private Proxies Buy 50 Private Proxies Buy 100 Private Proxies Buy 200 Private Proxies Buy 500 Private Proxies Buy 1000 Private Proxies Buy 2000 Private Proxies ProxiesLive Proxies-free.com New Proxy Lists Every Day Proxies123